Need formula, possibly IF, THEN???

Hard to explain, I am trying to make one field equal to another field if a certain value is selected from a list in another field. For example:

Column A on Tab 1 has a list which is populated from a column of values in Tab 2. If a value is selected in the list, I want the corresponding value to auto-populate in the correct field (example in B in Tab 1, below).

Tab 2:
A B
1 Apple $5
2 Pear $3
3 Orange $2

Tab 1
A (list) B
1 Pear (should equal $3)
2 Apple (should equal $5)

Sorry, hard to explain, hope this makes sense!

Amazing! Thanks so much!